Terminal server applications whose extended variants are also known as virtual desktop applications (VD applications), make it possible to centralize required hardware at one location or only a few locations, such as data centers, since only standardized hardware providing the necessary input/output means is required at the terminals. This allows, inter alia, centralizing management of the application, data processing and data protection. Hardware defects at the terminal do not affect the application and all terminals operate with the same version of the application.
The proliferation of mobile terminals with mobile data links makes it possible to use the mobile terminals, for example a tablet computer or a mobile phone, as a terminal.
When a VD session is started and executed on the terminal, the user has access only to the applications and data residing on the VD-Server. Local applications, i.e. applications installed on the terminal, cannot access the data on the server and applications installed on the VD-Server cannot access data stored on the terminal, for example on the mobile terminal. The only resources of the mobile terminal, which the user can use as part of the session, are those the user needs for controlling this session. These are, for example, a keyboard that can be virtually displayed on the screen or that may actually be physically present, the display screen and a pointing device, typically a mouse or a touch screen. Other resources are not available to the user as part of the session.
If in the context of the application, the user wants to print modified or generated data, then the user must have access to a printer connected to the server, for which the application, the data are processed for printing subsequent to a print request by the user, thereby generating print data that the server may then forward to the printer.
One or more printers may have been set up for the user in the VD session. These are printers located on the corporate network. The user is advantageously at his workplace. However, if the user is traveling with his mobile terminal outside the company premises, he can no longer use these printers. If the user wants to print a document that is accessible only via the closed network, multiple steps are required; if only one of these steps fails, the user cannot print the document. In the first step, the user must copy the document from the corporate network onto his mobile terminal. From there, the document is sent to the printer, with the assumption that the document is in the correct print data format. The user can evaluate this only when he has the actual print in hand. Since he has no other support, he must convert the document to the proper format in the corporate network. This task is usually handled by the printer driver, which subsequently forwards the converted document to the printer. No provision for user intervention is made at the point. The user must therefore interrupt the usual printing process to gain access to the print data. It is hence obvious that in the prior art a user who performs a VD-session on a server via a mobile terminal and a mobile data connection faces major problems when outputting one of the documents stored on the server on a locally available printer.
Mobile terminals, on which, for example, the operating system iOS or Android is installed, are equipped with the functionality to be contacted by a notification server, which provides the necessary infrastructure to contact and to send data to the mobile terminals via a unique ID regardless of existing network topologies. This is strictly a one-way communication from the notification server to the mobile terminal.
In the conventional process, the user starts a print job by operating the user interface of the employed application on the VD-Server. This usually involves selecting the menu item “Print” or directly pressing a button. A few more steps are still possible thereafter, such as selecting the desired printer, when several printers are installed, and setting parameters for the print job, for example, the paper size or two-sided printing. Thereafter, the print job on the server is forwarded to the printer driver of the selected printer, which converts the data into the required format and forwards the data to the printer. This procedure is not practical for mobile terminals located outside of the network, since the user has no access to the printer and hence cannot access the actual print.